The present invention relates essentially to a shock and/or vibration damping device for use between a supporting element and a supported element.
There are already known shock and/or vibration damping devices for use between a supporting element and a supported element, which comprises a body adapted to be assembled to one of the said elements and having a preferably substantially cylindrical cavity in which is introduced a piston whose rod is adapted to be assembled to the other one of the said elements. Such devices also comprise at least one resiliently so-called supporting deformable membrane arranged in the said cavity and interposed between the piston head and the cavity bottom wall facing it. Such devices are described for instance in applicant's French Pat. No. 70 03 678.
Such apparatus offer excellent multi-directional vibration-damping efficiency. Their shock absorbing capacity is good along their vertical center line owing to the considerable travel resulting from the provision of a resiliently deformable membrane.
On the other hand, their lateral shock damping capacity is relatively low owing to the limited horizontal displacement with respect to the center line of the damping device.
Thus, it may be said that the various damping devices known hitherto suffer from a certain number of drawbacks, one of which is their relatively low lateral-shock absorbing efficiency resulting from their very limited horizontal displacement.
Moreover, the arrangement in series of several membranes sliding on a fixed vertical axis pin, a very favorable arrangement for absorbing vertical shocks, is impossible in the horizontal plane. On the other hand, any attempt to obtain a significant lateral displacement on a single supporting membrane would result in excessive dimensions inconsistent with limited available spaces.
On the whole, therefore, it is difficult to obtain a lateral shock absorbing capacity that is satisfactory without lateral displacement being significant. This is all the more difficult as the said displacement must be small if a damping device suitable for practical purposes is to be obtained.